In recent networks, there is a service chain system that transfers packets through network (NW) functions such as firewalls (FW) and proxies virtually arranged on a communication route in response to a request for an access from a base to an external site or from a base to another base. A communication route via virtual NW functions is called a service chain.
Conventionally, the NW function works on a physical NW apparatus such as a NW server. However, owing to recent performance improvement, a general purpose server has been enabled to implement the NW function even by a software processing on the general purpose server. Accordingly, operation of the NW function has started in a mode where a program of the NW function runs on a virtual machine in a virtual environment of the general purpose server. A software processing for a NW operating on a virtual machine is called a virtual network function (VNF).
However, as a result of a shift of the operation mode of NW-related processing such as data transfer from a physical NW apparatus to a VNF of software processing on the general purpose server, processing performance of data transfer drops in some cases. For solving this problem, the NW-related processing is scaled out by implementing a plurality of programs in parallel and operating virtual machines on a plurality of servers in parallel such that load of data transfer is distributed, and thereby processing performance of data transfer is improved.
FIG. 32 illustrates an example of an arrangement configuration of a service chain. A service chain 200 illustrated in FIG. 32 arranges, for example, VNFs 201 such as FWs 201A, intrusive detection systems (IDSs) 201B, and Proxies 201C. Further, in the service chain 200, load balancers (LB) 202 for distributing the traffic are virtually arranged upstream of the VNFs 201. The LB 202 distributes the traffic to the VNFs 201 arranged downstream thereof. As a result, drop of the processing performance by the software processing is suppressed by distributing loads of the transfer processing of the VNFs 201.
Related techniques are disclosed in, for example, Japanese Laid-open Patent Publication Nos. 2015-154325 and 2016-46603, and International Publication Pamphlet No. WO 2014/208661.